BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Acorn Woodpecker In Great Basin

All regionsGreat BasinForest birds

Acorn Woodpecker in Great Basin has surged: up 566% on the route-weighted index since 1972.

+566%Since 1972TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
6Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
39YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Acorn Woodpecker has surged in Great Basin: up 566% on the route-weighted index since 1972.

Acorn Woodpecker In Great Basin Population Forecast

If the recent trend holds, Acorn Woodpecker in Great Basin is projected to rise about 19% by 2024 — from 0.28 in 2019 to a central estimate of 0.34 (95% range 0.16–0.52). A 5-year backtest shows a typical error of ±24.3%, with 100% of held-out values landing inside the 95% band.

+19%Change by 2024TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.34Projected 2024 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.16–0.5295% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±24.3%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Acorn Woodpecker in Great Basin is projected to rise about 19% by 2024 — from 0.28 in 2019 to a central estimate of 0.34 (95% range 0.16–0.52). A 5-year backtest shows a typical error of ±24.3%, with 100% of held-out values landing inside the 95% band.19702024
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20200.320.140.49
20210.320.140.50
20220.330.150.51
20230.330.150.51
20240.340.160.52

Routes In Great Basin

Routes recording Acorn Woodpecker in Great Basin.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Iron GateCALIFORNIA412019
NubieberCALIFORNIA42018
Fall River MillsCALIFORNIA32011
MacdoelCALIFORNIA22010
LikelyCALIFORNIA12015
BartleCALIFORNIA12009

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.